1. Field of the Invention
The present invention relates to the field of automatic control, and particularly to a universal capacitance-type touch inductive switch assembly for a faucet. This switch assembly is a DIY means which controls water supply by means of body induction touch, and particularly to a DIY control box which controls water supply by means of body capacitance induction touch. The DIY control box can be connected to all existing faucets in a modular fashion to realize the functions of a capacitance-type touch faucet.
2. Background of the Invention
The faucets commonly comprise top screwing switch type faucets and lifting handle type faucets. Among faucets for use in the kitchen, lifting handle type faucets are applied more commonly. The reason is that in the kitchen the faucets are used more frequently, and this kind of faucet is more convenient in operation.
The lifting handle type faucets generally operate in the following manner. A switch valve and a water mixer are integrated in the lifting handle. If the handle is lifted upward, the switch valve is opened so that the faucet supplies water. If the handle is pressed downward, the switch valve is opened so that the faucet stops supplying water. When the handle is rotated to the left or right, water is mixed at outlets of a cold water line and a hot water line which supply water to the faucet, so that the temperature of water is adjusted.
During use of such a faucet, it is not convenient to operate the handle if the user has his hands with oil or liquid detergent, since the handle of faucet would be stained. If the user holds anything in his hands, it is not convenient for him to adjust the handle switch. In addition, since the handle switch is a pure mechanical structure, the problem of mechanical wear occurs if it is switched frequently. After use for a long period, the faucet may not be closed properly or water may be leaked from it.
To this end, U.S. Pat. No. 6,962,168B2 discloses a capacitance induction faucet. A capacitance induction module is arranged in the faucet, the spout of the metal faucet acts as an electrode of the capacitor, and the human body acts as the other electrode of the capacitor. When the body touches the metal faucet spout, it constitutes the capacitor with the metal faucet spout. This induction capacitance is generally several pF to dozens of pF. The weak high-frequency current produced by the capacitance induction module flows to the ground through the body. When the capacitance induction module detects such a weak current, the action that the body made a touch is determined. Such a touch can be a touch by an arm, instead of moving the handle with a hand, so that the convenience of use is enhanced. In the technical solution as disclosed in U.S. Pat. No. 6,962,168B2, a solenoid valve is connected in series at a site downstream the water mixing valve in the water supply line. When the controller detects a touch, it sends a pulse signal for controlling opening and closing of the solenoid valve. During use, the mechanical switch to which the handle is connected is opened firstly. In a state the mechanical switch is opened, the opening and closing of water supply is realized by the touch faucet spout.
This faucet is of an integral type. In order to put it into use, the faucet at home should be replaced, which brings about waste and inconvenience. In case that the size of installing holes for new faucet is different from that the original faucet, it is required to drill new installing holes by means of a special drilling tool, which make it very difficult to install the faucet. Therefore, there is an urgent need for an assembly which is applicable to all existing or on-sale metal faucets, and can also realize the touch inductive switch operation.